[poppler] Implemented Type 4/5 shading for Splash Device

[Christian Feuersaenger]

Hi Albert,

thank you for the fast reply and your positive answer!

I will use the next days to apply the xpdf patches to libpoppler.

I intent to patch the patched triangle refinement to your stable branch, 
which appears to be the poppler-0.14 (?). I consider it to be a bugfix.

The interpolated shader is not yet stable and may need some revisions. I 
will continue working on it, preferrable on a separate branch.
If you like, I can try to make a www git repository somewhere such that 
you can fetch my changes and merge them to whereever you want.

For the moment, you find my test.pdf attached. it has been generated 
with latex and the unstable version of \usepackage{pgfplots}, 
http://pgfplots.sourceforge.net/; I also attached the .tex sources.

So, thank you for the positive feedback.

Best regards

Christian

 >> >  I am sure my additions are valueable and propose them for usage in
 >> >  libpoppler: the bugfix/speed improvement is directly usable and 
stable
 >> >  and the lowlevel shader will need some more time. I could also 
use some
 >> >  advice to get the integration with transparency, blending and 
whatever
 >> >  correctly. I started with the xpdf sources, so I would also 
appreciate
 >> >  any hints how you communicate changes between xpdf and libpoppler 
if you
 >> >  are interested in my proposal.
 > Yes, we are interested in your patches, basically what we would need 
you is to
 > provide a patch over poppler sources, you can choose wheter you want 
to make
 > it against git master branch, git poppler-0.14 branch or the released 
0.14.0
 > tarball.
 >
 > Also it would be interesting to have the PDF you have used for testing.
 >
 > Thanks,
 >    Albert